Unable to open OneNote webUrl in iPhone?

Question

I am using OneNote API for creating note in OneNote from my ios application. After creating note api returns two url clientUrl and webUrl.

clientUrl => Link open page in the installed client 
webUrl => Link to open page in OneNote Online

Now the problem is webUrl is successfully opening in iPad but not in iPhone. In iPhone i am getting safari can not open the page.

This is the code i did for opening webUrl.

NSURL *url = [NSURL URLWithString:webUrl];
UIApplication *application = [UIApplication sharedApplication];
[application openURL:url options:@{} completionHandler:nil];

Also i tried to open clientUrl but what if user have no OneNote app installed in device ?

Please help me on this why i am unable to open URL ? Is there any specific reason behind this ?